A mandibular advancement measuring and positioning device provided with an instrument with an upper slider and a lower slider, means to measure and position the relative displacement of the upper and lower sliders, and upper and lower trays at one end of the instrument, the upper and lower trays being attached to the upper and lower sliders, respectively,
- wherein the lower slider is divided into a fixed part and a pivoting part joined to an end of the fixed part, the upper slider and the lower slider being joined by means of a recess that allows a relative slide of the upper and lower sliders,
- wherein the pivoting part of the lower slider is provided with a vertical opening control, and
- wherein the vertical opening control is configured to create a gap between the upper slider and the lower slider.